Reverse sash cramps (to spread, not compress)

[Jamp]

Hi All

I need a pair (at least) of devises which act like a jack to spread two pillars which are ~500mm apart. Bottle jacks would be ideal but I doubt they're available in such a size. A sash cramp operating in reverse would also do fine. But most that I see are only set up to compress. Some might have a reversable end stop, but the screwing end seems only to work one way. Does anyone know of a sash cramp available that has a usable surface/pad on both sides of the screwing end?

 

[Burnerman]

How about one bottle jack plus a length of stout timber to give it the reach?
Hire centres do jacking pads which are similar - or even a small Acro prop?
John

 

[Thermo]

ceratinly do acrow props small enough for trench boards etc

 

[crank39]

What sort of pillars and what sort of force would be required?

My suggestion would be quick grips but without knowing the application its hard

 

[Trazor]

Car jacks with appropriate lengths of wood to suit.

 

[big-all]

what are you trying to move and how far

by far the simplest way to lever if you want sustained preasure is 3x2" in this case 415 long another 2 bits around 75mm long
another length to act as a lever from the floor up
tape one 75mm length to one pillar/leg and at the other end tape the other to the bottom off the lever on the 2" side' tape the lever to the pillar
lay the 415 bit accross between the leg/pillar at one end and the lever at the other but sitting on top off 75mm bits

you now have 10mm gap move the lever over to fill the gap now assuming your lever is at least 400mm long you have a 4to1 leverage
to tension pull the lever and drop a bit off timber down the back to hold position

now the length off the lever and the height off the supporting blocks determin the power exerted

you can off course use 2x1 or 2x2" dependant on room and force reqired

 

[Jasonb]

The Jorgensen "Pony" pipe clamps can be reversed to use as spreaders

If you look just to the left of the digger you can see where I'm using them to jack up a 12ft 8x4 oak beam on this deck.

A "Hi-lift" jack will also do the job with about 3 tonnes of force

Hydrawlic spreader ram as used for car repairs, should be able to hire one

Or a trench prop as thermo suggests

Jason

 

[Hitachimad]

Carver clamps.... piher bar clamps...Body repair type hydraulics...farm jack...or buy a couple of sets of clamp heads, and make your own.

If it doesn't need much force, and doesnt need to move far, cut something slightly longer than the opening, put in at an angle and knock it down untill its straight. Never underestimate the power of such a simple thaing as a wedge

 

[muggles]

Irwin Quick Grip XP Bar Clamps are reversible so that they also spread, and can exert up to 250kg of force on whatever you're spreading or clamping. See general brochure here, available in a variety of sizes
http://www.irwin.eu/pdf/IR_QG_KFS_XP_UK_noprice.pdf
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[PrenticeBoyofDerry]

I have a pal called Samson

 

[muggles]

I have a pal called Samson

Does that mean you're Delilah?

 

[crank39]

Don't you just hate it when the OP won't elaborate and clears off after one post?

 

[Jamp]

Thanks for your tips. I must apologise for not updating this and not elaborating as requested.

I solved the problem another way, but I'll explain for your interest/reference.

I was having to take apart a shower cabin which had been installed incorrectly. This is the cabin: http://www.indigoshowers.co.uk/cabs701sn.htm

The glass panels have aluminium frames which sit in channels in the vertical pillars at the corners. They had been siliconed into the tight fitting channels, so I couldn't get them out, no matter how much I tried with craft knives etc to slice the silicone at the sides of the channels, but of course I couldn't reach the butting face, which was where most of the silicone was it transpired.

In the end I got hold of a metre long length of 10mm steel rod, which a blacksmith ground a blade/flat screwdriver bit onto the end of. I drove this down into the channel slicing through the silicone and wedging the frame out of the pillar. This worked very well and caused minimal damage. It was definitely a much better way of doing it than a sash cramp would have been, as I'm sure that would just have bent the pillars around themselves as the frames and channels were stuck fast. I'm sorry I didn't explain better and get the benefit of your advice then!

Cheers,

Jamp[/url]